Propelling device



Feb. 15, 1938. H. COANDA PROPELLING DEVICE Filed Jan. 10, 1936 2 Sheets-Sheet 1 INVENTOR HENRI COANDA ATTORNEY6 FBTIE, 193s. I H DA- 2,108,652

PROPELLING DEVICE Filed Jan. 10 1956 I 2 Sheets-Sheet 2 a FNVENTQRJ Z99 HENRI COAND ATTORNEYS Patented Feb. 15, 193% 2,108,652 ruorELLme DEVICE Henri Coanda, Elicliy, France, assignor to Socit Anonyme dEtudcs des Brevcts et Procds Goanda-So it Coanda, a corporation of France Application January it, 1936, Serial No. 58AM In France .lauuaryli5, 1935 10 Claims.

The present invention relates to propelling devices in which there is produced a suction zone in front of the body in motion on which the propeller is mounted, this suction being such that the body in motion is propelled under the influence of the atmospheric pressure existing at the rear of the propeller.

4 The object of the present invention is to provide a propelling device of this kind which is better adapted to meet the requirements of practice than those made up to the present time. According to the invention the propeller is composed of an annular structure of suitable axial section, on which a ring fits in an adjustable l8 manner, said ring being concentric and constructed in such a manner that a very narrow gap is formed between it and said annular structure, through which gap compressed gas escapes outwardly along a frontwardly directed line, the

[ axial sectionof said annular structure consisting of a curve tangent to this line and having its convexity toward the front, while the axial section of said ring is a line making a substantial angle with said first mentioned line.

Furthermore the ring and annular structure are hollow, at least to a certan depth so as to allow air from the space ahead of the propeller to flow through their central portion and out behind the annular structure. This prevents any suction at the rear of the annular structure so that the whole of the suction is in front thereof, and the motion of the body is ensured by the difference between the pressure at the front and that at the rear.

Preferred embodiments of the present invention will be hereinafter described with reference to the accompanying drawings, given merely by way of example and in which Figs. 1 and 2, show in perspective and sectional views respectively a first embodiment of the invention,

Fig. 3 is a sectional view of a modification, In the embodiment of Figs. 1 and 2, the body of the propelling device according to the invention includes an inner element l and a tubular part 2, fitted thereon and provided at 3 with screw threads for fixation of a tube t. This structure carries a series of tubes 5 opening into an annular member 6. Another annular member 8 is screwed at l on member 6, so that the narrow annular interval 9 between members 6 and 8 can be adjusted at will.

Member 6 may be made of a single piece or consist of two rings 6', 6" screwed to each otherat l0, to".

(Cl. bit-t3) In the embodiment of Fig. 3, the streamline body it contains a part screwed to the member l3. Tubes it are provided in member l3 and secured bythe screw, thread in a ring l5 of suitable profile upon which a ring it is fixed by 5 screw threads; ll, so that this ring Hi can be adjusted in position with respect to ring l8.

Between ring it and ring ld there is left an adjustable narrowxannularinterval 89, ring it being however constructed so as to form a cir- 10 cular chamber 2t between said ring and ring iii.

The propeller works in the following manner: The compressed gas, which may consist of superheated steam or a combustible 'mixture or some explosive mixture or even compressed air, is l5 supplied through tube t, flows through the annular space formed between elements l and 2, passes through tubes 5 into the narrow annular interval 9 between the element 6 and ring a and escapes into the atmosphere.

The fluid film expands and exceeds its initial volume, and, owing to the fact that on one side of the outlet of passage t, annular member 6 is substantially tangent to the fluid sheet escaping from 9, whereas, on theother side, the edge of 25 member ii makes a substantial angle to the directionof said sheet, the latter flows along the front face of member 6, following the path indicated by arrows 1. Thus in the space marked in dotted lines a rush of fluid is created toward which 30 the surrounding air is drawn in the direction of the arrows 1 provided the pressure of the motive fluid is sufficient.

Therefore the propeller, owing to the suction created at its front part, has a tendency to rush '35 frontward under the action of the pressure existing behind it, drawing along the structure on which it is mounted provided the outflow is sufflcient to create a momentum at low speed and in great masses of the surrounding air, equivalent 4,0 to the drag of the body in which the propeller is mounted.

Moreover the surrounding air circulates through the central free portion in the direction of the arrows F, at same pressure, so that be- 45 low the part 6 a counterpressure is created relative to the suction in front of the same, which counter pressure consequently adds to the action of the suction created in front of part a.

The same applies in the case of Fig. 3. The 50 gaseous mixture under high pressure which is to expand after entering the chamber formed by part l2, passes through tube it, starts expanding in chamber 20 and escapes through annular interval is following the front face of element N5, 55

creating in front of it a zone of very strong suction represented by dotted lines.

It is evident that the shape of elements such as 6' and I6 and the thickness of annular interthrough the inner aperture thereof and thr ugh said space to the lateral sides of said body, another annular member rigidly flxed to said body in coaxial relation with the first mentioned anvals 9 or!!! are-calculated in such a mannerthat nularmember and ahead thereof, said'members 5 a certain-expansion of the compressed motive being so positioned andshaped as to tform befiuid permits of obtaining a momentum which tween them ,an annular interval with a flaring ensures the displacement ofthe body. outlet opening to the atmosphere in a frontward Inageneral manner, whileI have, intheabove direction, the rear edge or lip of said outlet 10 description, disclosed what I deem to be practiformed'by the front surface of the first meni0 cal and eflicient embodiments of the present intioned annular member, being of rounded shape vention, it should be well understood that ,I do starting tangentially to said frontward direction not wish to be limited thereto as there might'be on the outer side thereof, with its convexity tochanges made in the arrangement, disposition ward the frontgwh'ereas the front edge or lip of and form of the parts without departing from said outlet, formed by the front surface of the 15 the principle of the present invention as compre -jj; second mentioned annular member, starts at an hended within the scope of the appended claims. I angle to said direction on the inner side thereof,

It may be noted that in Fig. 1 the member and means for driving outa fluid under high 8 and -in -Fig.-3 the part ldextend'at least with pressure through said annularoutlet. M i

theedge intoa recessat the front oLthe mov- A 'propellingjdevice of th type) described, 20 ing; body, with the result that the air or fluid hich comprises,"incoriibiriation, a bOdy an'an. issuingfrom the narrow slot first strikes the nular member rigidiyiixedjito"saidfbofdy'atthe curved portion of the airfoil or wing shaped front, part thereof, with a spacefbetwe'en the member so as to follow its curvature forwardly rear face of saidjmemberandsaid bodyfwhereand then outward radially and subsequently rearby air from the front of said member can'fflow 25 wardiy. r i, i i through the inner aperture thereof and through Having now fully described my invention, I said space to thelateral sides oisaidfbodmanclaim: I other annular member rigidly'ilxedto said'body, irhdpropelling device of thetype described, in coaxialrelation with'vthe first 'mentionedam which comprises, inicombination, a body, anannular member, aiid,aheadgthereof,said members 30 nularmemberlrigid with said body at the front being so positioned*'and,shaped astojfqrm be part,thereof,- .another annular member rigid with tweenthem an' annular chamberjhaving an an: said body, coaxial with the first annular mem nular flaring outlet openingtd'the atmosphere 7 her and located ahead thereof, so as to leave in a frontward direction, the"'rearedgebr' lip between; said members a narrow annular inter of saidoutlet, formed by the, front surface 01-35 valwithadlaring outlet opening to the atmos the firstfmentioned annular: member, emg; of phereina frontward direction, the rear edge or rounded shape startinglftangentially td'sa'id"front p of a d ut formed -t e n surf e ward direction on the v,oujte side thereof, with its of th fi te e .a me be b in convexityltowardjthe front, n dstne" front 40 of rounded shape starting tangentially o said edge or lip of said outlet; formedby. meow 40 frontwarddirectionon the O e S ere f. surface of the second mentioned annularfmemits ex ty toward the front, whereasthe berjstarts at an angle, to said direction some:

- mm? ,8 lip of said q t formed Wth inner side thereoflfan'dmeans for feedinga front surface of the second mentioned annular fiu id under mgg s gw said hma am member, starts'at anangle to said direction on b b tw d m mb t m cm d 45 t inner slde thereof, and means t driving means including a'plurality or tubes extending utafl dundm highp e h ou said anfrom said body and opening into Saidbharnbr.

, nularoiltlett, 5 A propelling device of the typedescribed A propelhnsgd vm o th type scr d, which com rises, in combination, a'podyof hol so which comprises, 3 b nati a bo a low shape formingajcontainer for fa' fluid on: nular member rlsldly fixed to s d at t der high pressure, anannular member "rigidly fr nt part e o a e nnular member 112- fixed to said bodyat'the front part thereof, wan

- idl iq Said Q Y in coaxial relation t a space between said body and the rear iacebf the first annular member a ahead thereof, said said memben'whereby air oanfiow from the from membershbeing 80 positioned and shaped s to of said anndlar member, through the central 55 form between them a narr w annular interval aperture thereof and through 'saidspace, to the wi ha flarin o t et ope to t e m phe e lateral sides of said body, another annular main in a front a d d e t the .rear e fo p ber rigidly fixed tosaid first mentioned annular of said outlet,formed by the front surface or member coaiiiallytherewith and ahead thereof,

the first mentioned annular member, being 0f said members being so positioned and shaped as 60 u de Shape Starting n e lly t0 said'frontto form'between them an annular chamberhavward direction on the outer side thereof, with m 'an l 'g un oij mng its convexity ow rd th front, whereas the front mosphere in a frontward direction,'the rearedge ed e or lip of s d t e ed b t e front or lip of said outlet, formed by the front surface sur a e of th s d mentioned a nu r mmof the first mentioned annular'member, being of 65 lt S a an ng e to said direction on the rounded shape starting tangentially to said frontinner side thereofjandnmeans for driving out ward dire'ction'on the'outer side 'the're'ofy with a fluid under high pressure through said annuitsconvexity toward the front; whereas the front lar outlet. H I edge or lip of said' outlet, formedbythe front '3. A'propelling device of the type described, surface of the second mentioned annular mem 70 which comprises, in combination, a body, an anber, starts at an angleto said direction onithe nular member rigidly fixed tosaidbody at the inner sidethereof, and a plurali y of pip s 99nfront part thereof, with a-space between the nesting the inside of said'bodywi'thsaid a'nf rear face of said member and said body, whereby nular chamber for feeding fluid under high presair from the front of said member can flow sure to said chamber. 75

2,108,652 6. A propelling device of the type described,

which comprises, in combination, an elongated body having one end serving as a forward portion or nose, at fixed surface member of wingshaped section rigidly carried exteriorly upon the forward portion of said body in spaced relation to the latter and with the chord of said section practically transversely disposed with respect to the forward direction upon the body, the front surface of said member being convex in said forward direction and arching rearwardly away from said body from a recess or depressed portion in the foremost part of said forward portion, rigid spaced means upon said fixed member spaced a small distance from the latter member in said recess or depressed portion so as to determine at least one narrow slot communicating with; the interior of said body and allowing a sheet of fluid to be projected at high pressure from within the body out through said slot and against the convex front surface of said fixed member in said recess and caused to follow said curved surface first forwardly out of the recess and then outwardly and rearwardly along the arching portion of said curved surface upon said fixed member, and open means upon the forward portion of said propelling device allowing free access of air to the rear surface of said fixed surface member between the same and the body independently of the fluid supply escaping from the interior of said body through said narrow slot.

'7. A propelling device according to claim 6, wherein the fixed surface member is annular so as tosurround the nose of the device, and the .slot means extends around said nose in the recess which is also extended about the device to be annular in form.

8. A propelling device of the type described. which comprises, in combination, an annular elongated body having one end serving as a forward portion or nose, at fixed annular surface member of wing-shaped section rigidly carried exterlorly upon the forward portion of said body in spaced relation to the latter and surrounding the same with the chord of said section practically transversely disposed with respect to the forward direction upon the body, the front surface of said annular member being convex in said forward direction and arching rearwardly away from said body, rigid spaced means upon said fixed member spaced a small distance from the latter member so as to determine at least one narrow slot communicating with the interior of said body and allowing a sheet of fluid to be projected at high pressure from within the body out through said slot and caused to follow said curved surface outwardly and rearwardly along the arching portion of said curved surface upon said fixed and annular member, there being a free and open passage extending rearwardly from the forward portion of the device and communicating in unbroken manner with the space between said fixed annular member and said body allowing atmosphen'c air to enter freely and relieve any tendency to form a vacuum upon the rear surface of said annular member, and a plurality of fluid supply tubes connecting the interior of said body with said narrow slot through said space between the annular fixed member and said body and independently thereof.

9. A propelling device according to claim 8, wherein the fluid supply tubes serve as the exclusive mechanical means for supporting the fixed annular member upon and spacing the same away from the main body of the device.

10. A propelling device of the type described, which comprises, in combination, an elongated body having one end serving as a forward portion or nose, a fixed annular surface member of wing-shaped section rigidly carried exteriorly upon the forward portion of said body in spaced relation to the latter and surrounding the same ward direction and arching rearwardly away from said bodyfrom an annular recess or depressed portion in the foremost part of said forward portion, rigid spaced means upon said fixed member spaced 9. small distance from the latter member in said recess or depressed portion so as to determine at least one narrow slot communicating with the interior of said body and allowing a sheet of fluid to be projected at high pressure from within the body out through said slot and against the convex front surface of said fixed member in said annular recess and caused to follow said curved surface first forwardly out of the recess and then outwardly and rearwardly along the arching portion of said curved surface upon said fixed annular member, there being a free and open passage extending rearwardly from the forward portion of the device and communicating in unbroken manner with the space between said fixed annular member and said body allowing atmospheric air to enter freely andrrehave any tendency to form a vacuum upon the rear surface of said annular member, and a plurality of fluid supply tubes connecting the interior of said body with said narrow slot through said space between the annular fixed member an said body and independently thereof.

HENRI COANDA. 

